Many items, such as tools, automobile parts, fixtures, etc., have a metal structure that is combined with comparatively less durable parts or materials, such as coatings, gaskets, fiberglass, enamels, paints, etc. In general, the less durable parts or materials in such items deteriorate more quickly than the metal structures that they are combined with. Rather than discarding an item when the less durable parts or materials deteriorate, the metal structure of the item can be salvaged by removing the deteriorated material.
A conventional device for removing material from a metal structure is disclosed in U.S. Pat. No. 3,830,196 to Guttman et al. In FIG. 1, Guttman discloses a stationary painting line in which parts are hung from aluminum hangers 40, and advanced through a painting zone 20 by a conveyor 10. The painting line includes a burn-off oven 28 for removing paint that has accumulated on the aluminum hangers 40. Guttman's painting line is a static structure, and occupies a large space. In addition, workers located near the painting line may be exposed to harmful combustion products produced in the bum-off oven 28.
U.S. Pat. No. 4,270,898 to Kelly discloses a conventional burner control method for removing materials from metal parts 5 in a reclamation furnace 1. Kelly's reclamation furnace 1 is also a static structure, and the parts 5 must therefore be brought to the furnace 1 for processing. In addition, workers located near the furnace 1 may be exposed to harmful combustion products.
However, prior art furnaces have required heating of the entire part so that not only the surface but the core of the part is heated to a high temperature in order for the paint or other coatings to be burned off. Since the entire thickness of the part is heated, the characteristics of the metal are often changed. Thus, the part may be warped or otherwise deformed. In addition, parameters such as hardness, strength, etc. may also be affected. This is especially true for materials which are originally heat treated in order to increase their strength.